Cathryn Throup, from Worcestershire, tweeted on Monday 10 July: “Extra rules for the use of semi-colons, which only markers are entitled to.”

Regarding the size of the punctuation mark, the rules stated: “The comma element of the semi-colon inserted should be correct in relation to the point of origin, height, depth and orientation.

“Where the separation of the semi-colon is excessive, neither element of the semi-colon should start higher than the letter ‘I’. The dot of the semi-colon must not be lower than the bottom of the letter ‘W’ in the word ‘tomorrow’.

“The orientation of the comma element of the semi-colon must be inclined to the left or straight down. It cannot incline to the right.”

A primary teacher from Preston in Lancashire shared a photo of four of her kids’ answers - all with the semi-colon in the right place.

However she said she felt “frustrated” as two were marked correct and two were marked incorrect.

Another headteacher, tweeting at @Oldprimaryhead1, from Somerset, said as well as harsh punctuation marking, children were marked down on the placing of the letters “p” and “k”.

He wrote on his blog ‘Why SATs Must Change – Time to Act’: “I have always been concerned about SATs but these last two years have highlighted these concerns to a point at which I feel that I can no longer just sit back and moan.

“The tests seem to be marked inconsistently. There are many examples on social media. SATs impact on some children’s wellbeing in very negative ways. As part of this process I think it is important that we get better data on this.”

Many other teachers have used the hashtag #SATsshambles to share their own examples of marking inconsistencies.

A Department of Education spokesperson told HuffPost UK: “The key stage 2 tests assess the delivery of our new primary curriculum that ensures children are mastering the basics of literacy and numeracy. Markers are given additional guidance to ensure the published mark schemes are applied consistently and fairly, in this case to ensure children are using and forming punctuation correctly.

“Should any school feel mark schemes have been applied inconsistently or incorrectly they can submit pupils’ scripts for review. Reviews are carried out by experienced supervisory markers who use their judgement to ensure no child is unfairly penalised.”